While doing meditation body gets start heating during prana exercise and body shakes and energy rise upwards and focus gets centred between the eyebrows.
Is this a new experience? Have you been meditating for weeks, months or years? I can only comment generally not knowing more about your meditation practices but here are some thoughts:
1. “Searing heat” in the spine should at all costs be avoided and if this happens stop meditating at that time. (You can always try again later.)
2. I assume, however, that you are NOT describing an intense and uncomfortable experience of heat; just a general sensation of heat and shaking in the body. Is this correct?
3. Taking into account, therefore, #1 and #2 above as not applicable to you, I would say that what you describe is very likely a temporary state that can go away over time with the additional suggestions below.
4. You might be “trying too hard” when you do pranayam exercise. When there is too much will power and when relaxation is not emphasized then heat builds up in the body and in the mind.
5. Therefore, make RELAXATION your primary intention and effort when you begin to meditate. Let even pranayam be refreshing, relaxing and enjoyable. Too many people “huff and puff” like the “big bad wolf” trying to blow down the “little piggy’s house!” (do you know this childrens’ story: the Three Little Pigs?) Yes, there are some very aggressive breathing exercises (e.g. Bhastrika pranayam or kapalabhati), but if you are doing these then I recommend you switch to cooling pranayams like Sitali or Sitkari pranayam (but don’t overdue it!) Do simple, diaphragmatic breathing (inhale, hold, exhale to equal counts).
6. Do you chant? Is devotion part of your meditation practices, too? Devotion soothes the heart and calms the mind. Will power or concentration must be balanced by relaxation and devotion to God and guru.
7. Before sitting to meditate, you should do some simple stretches to relax the body. Yoga postures are excellent. Ananda teaches Paramhansa Yogananda’s excellent ENERGIZATION EXERCISES. These can be learned on YouTube (search for Energization Exercises) or on the Ananda Meditation App or, best of all, in person at an Ananda center near you. See www.AnandaIndia.org
8. Finally, in general what I see with students is that experiences such as you describe will tend to go away if we relax and stay focused with our practices until the sensations, like warmth or shaking, subside. Sometimes the subconscious and body respond by resisting meditation or “fearing” it with an increase of what seems like flushing, or as if being self-conscious. It is a matter of calmness. This is why stretching, chanting, and gentle pranayam are important: to ease the subconscious mind and its loyal attendant, the body, into the experience of meditation.
Try these and let us know, ok?
With unceasing blessings,
Seattle WA USA